Technical Field
The present disclosure relates to a method for fabricating microfluidic structures, especially relates to a method for fabricating microfluidic structures that patterns of the microfluidic structure are formed by utilizing pre-patterned double-sided tape, thereby extra packaging process is not required.
Description of Related Art
There exists a plurality of small-scaled materials in a natural world. For testing and researching these materials, small components having dimensions as low as μm or nm order are required. Conventionally, it is very difficult to fabricate devices equipped with such small-scaled components. Recently, as the progress on the science and the manufacturing technology, it is possible to fabricate devices equipped with such small-scaled components.
Microfluidic devices are widely used in biomedical equipment, fuel cells, heat exchangers, chromatography sensors and printer heads. Briefly speaking, the microfluidic structures are provided for a fluid to flow therein in order to transport or filter micro-materials in the fluid. In some cases, multi fluids are mixed in a microfluidic structure for observing reactions between many micro-materials, and achieving rapid transportation and testing. Recently, the microfluidic structures are widely used in biomedicine fields, for example, to utilize microfluidic structure to test or filter proteins or stem cells.
The fluid is not easily flowed in a microfluidic structure owing to the ultra-small dimension of the microfluidic structure. In a situation that without applying any outer driving forces, the fluid can only be driven by diffusion or capillarity effect. To the micro-materials with low diffusion coefficient (e.g. proteins), it will take a lot of time on flowing and mixing it to another micro-materials.
For solving issues on low fluidity of the fluids in microfluidic structures, many methods are provided for increasing diffusion rate of the fluids. In one method, the microfluidic structure are patterned to form complicated structures in order to increase contact area, thereby decreasing the diffusion length thus the diffusion rate can be increased. The aforementioned patterned microfluidic structure can also be applied extra driving forces such as voltage, electric field, pressure or micro-pump for driving the fluid.
Although the aforementioned patterned microfluidic structures can solve issues on low fluidity of the fluid, however, the original dimension of the microfluidic structure itself is very small. If complicated patterns are formed on the microfluidic structures, complicated processes are required, thereby leading to high manufacturing cost and time.
For example, FIG. 1 is a schematic view showing a conventional fabricating process for a microfluidic structure. In FIG. 1, a photo-sensitive material 120 is deposited on a substrate 110. Then, a photolithography process is applied to the photo-sensitive material 120 to form patterns for the microfluidic structure. Then, a metal layer 130 is deposited on the patterned photo-sensitive material 120, and an etching process is performed to remove the photo-sensitive material 120. The metal layer 130 is then patterned and formed on the substrate 110. The structure of the substrate 110 having the patterned metal layer 130 deposited thereon is called a master mold. After the master mold is formed, a gel-type material 140 which being solidified after heating is injected into the master mold, and the gel-type material 140 is patterned by the patterned metal layer 130. Finally, a patterned microfluidic structure is formed. Followed by cutting and bonding processes, a complete microfluidic device 150 is fabricated.
The aforementioned section discloses a conventional fabricating method for microfluidic structures. Although other fabricating methods are developed, the basic concept is similar with the aforementioned case. These kinds of processes are very complicated and related materials and equipment thereof are expensive as well as the fabricating time is long.